Bacterial cellulose an effective material in the treatment of chronic venous ulcers of the lower limbs.

Chronic venous ulcers (CVU) of the lower limbs (LL) are common and cause psychological changes and significant social impact, as they make the patient susceptible to pain, absence from work and social bonds. Some materials are suggested as dressings for the treatment of CVU, but they are expensive and are generally not available for use in public health services. To evaluate the efficacy of the treatment for lower limbs (LL) chronic venous ulcer (CVU) using bacterial cellulose (BC), gel and multi-perforated film associated. A randomized controlled clinical-intervention study was performed among participants with LL CVU, divided into two groups: experimental (EG), treated with BC wound dressing and control (CG), treated with a cellulose acetate mesh impregnated with essential fatty acids (Rayon®). The participants were followed for 180 days, evaluated according to the MEASURE methodology. Thirty-nine patients were treated, 20 from the EG and 19 from the CG. In both groups, the wound area decreased significantly (p < 0.001), the healing rate was similar to the CG. The mean number of dressing changes in the SG was 18.33 ± 11.78, while in the CG it was 55.24 ± 25.81, p < 0.001. The healing dressing of bacterial cellulose, gel and associated film, when stimulating the epithelization of the lesions, showed a significant reduction in the initial area, with a percentage of cure similar to the Rayon® coverage. In addition to requiring less direct manipulation of ulcers.

Use of bacterial cellulose film for repair of bile duct injury in pigs.

BACKGROUND/OBJECTIVE: The aim was to evaluate the use of bacterial cellulose film and bile duct autograft in repairing critical common bile duct injury in pigs. METHODS: A prospective experimental analytical study was carried out on 20 Sus Domesticus, Piau suidae swine, divided into a control group (n = 10) and an experimental group (n = 10) divided into two subgroups: bacterial cellulose film E1 and bacterial cellulose film E2 to which bacterial cellulose film was randomly allocated. The control group underwent two complete critical common bile duct sections 10 mm apart, while the experimental group with a single critical common bile duct defect underwent a 10 mm section of the longitudinal shaft with edge resection. The defects in the control group were treated with end-to-end conventional anastomosis using polyglycolic 6-0 surgical thread and the experimental group with bacterial cellulose film by continuous suture using the same material. The animals were clinically evaluated throughout the experiment on days D150 (bacterial cellulose film E1), D225 (control group), and D330 (bacterial cellulose film E2) and by intraoperative ultrasound examination related to histopathological and biochemical findings. RESULTS: The intraoperative ultrasonography detected the changes resulting from the common bile duct anastomosis in the control group that produced a considerable incidence of ductal narrowing and obstruction to the biliary flow. In the bacterial cellulose film E2 group, there was an increase in inflammation intensity, granulomatous reaction, fibrosis, and vessels density, without producing bile duct dilation in the ultrasonography assessment. Biochemical analysis of liver enzymes yielded results in the normal range confirming preservation of liver function at the different post-surgery time points. CONCLUSION: Bacterial cellulose film, when used as a graft for bile duct repair, proved to be a biocompatible material that produced a complete healing process and biliary flow continuity.

Effects of the encapsulation of usnic acid into liposomes and interactions with antituberculous agents against multidrug-resistant tuberculosis clinical isolates.

Mycobacterium tuberculosis (Mtb) has acquired resistance and consequently the antibiotic therapeutic options available against this microorganism are limited. In this scenario, the use of usnic acid (UA), a natural compound, encapsulated into liposomes is proposed as a new approach in multidrug-resistant tuberculosis (MDR-TB) therapy. Thus the aim of this study was to evaluate the effect of the encapsulation of UA into liposomes, as well as its combination with antituberculous agents such as rifampicin (RIF) and isoniazid (INH) against MDR-TB clinical isolates. The in vitro antimycobacterial activity of UA-loaded liposomes (UA-Lipo) against MDR-TB was assessed by the microdilution method. The in vitro interaction of UA with antituberculous agents was carried out using checkerboard method. Minimal inhibitory concentration values were 31.25 and 0.98 µg/mL for UA and UA-Lipo, respectively. The results exhibited a synergistic interaction between RIF and UA [fractional inhibitory concentration index (FICI) = 0.31] or UA-Lipo (FICI = 0.28). Regarding INH, the combination of UA or UA-Lipo revealed no marked effect (FICI = 1.30-2.50). The UA-Lipo may be used as a dosage form to improve the antimycobacterial activity of RIF, a first-line drug for the treatment of infections caused by Mtb.

Effects of the encapsulation of usnic acid into liposomes and interactions with antituberculous agents against multidrug-resistant tuberculosis clinical isolates

Mycobacterium tuberculosis (Mtb) has acquired resistance and consequently the antibiotic therapeutic options available against this microorganism are limited. In this scenario, the use of usnic acid (UA), a natural compound, encapsulated into liposomes is proposed as a new approach in multidrug-resistant tuberculosis (MDR-TB) therapy. Thus the aim of this study was to evaluate the effect of the encapsulation of UA into liposomes, as well as its combination with antituberculous agents such as rifampicin (RIF) and isoniazid (INH) against MDR-TB clinical isolates. The in vitro antimycobacterial activity of UA-loaded liposomes (UA-Lipo) against MDR-TB was assessed by the microdilution method. The in vitro interaction of UA with antituberculous agents was carried out using checkerboard method. Minimal inhibitory concentration values were 31.25 and 0.98 µg/mL for UA and UA-Lipo, respectively. The results exhibited a synergistic interaction between RIF and UA [fractional inhibitory concentration index (FICI) = 0.31] or UA-Lipo (FICI = 0.28). Regarding INH, the combination of UA or UA-Lipo revealed no marked effect (FICI = 1.30-2.50). The UA-Lipo may be used as a dosage form to improve the antimycobacterial activity of RIF, a first-line drug for the treatment of infections caused by Mtb.